In recent years, use of mobile communications devices for voice telephone services, email or text messaging services and even multi-media services has become commonplace, among mobile professionals and throughout the more general consumer population. Mobile service provided through public cellular or PCS (personal communication service) type networks, particularly for voice telephone service, has become virtually ubiquitous across much of the world. The rapid expansion of such mobile communication services has resulted in deployment of a variety of different and often incompatible wireless network technologies, in different jurisdictions or regions and in some cases as competing services within the same area. A large carrier may operate its network over a wide geographic area, however, to allow roaming of its subscribers outside even that coverage area, the carrier will have roaming agreements with operators of other networks in other areas. With the increase in international roaming, a demand has arisen for roaming into areas where coverage is provided by networks that utilize different and possibly incompatible technologies. To allow continued operation in regions where the local provider offers service via a different technology, station manufactures have developed dual or multi mode mobile stations, which have the capability of communicating via two or more wireless mobile technologies. As a corollary, the home operator's roaming agreements with other operators/providers now include agreements with local providers which operate networks that utilize different and possibly incompatible technologies.
Under typical roaming agreements, customers of the other providers may roam-in and use the home operator's network, whereas customers of the home operator may roam-out and use the networks of the other operators/service providers. However, different roaming agreements among the parties may have different terms. As a result, some agreements may be more favorable, and a particular home operator or service provider may ‘prefer’ for its customers to utilize the network of a particular other provider in certain areas. Hence, the network operators and their equipment vendors have standardized a number of signaling protocols and have developed various related mobile station hierarchical processing techniques to select an available network of a provider with which the home operator has the most preferred roaming agreement, that is to say the agreement requiring the home operator to pay the lowest rate to the visited network provider for the subscriber's service obtained while roaming into and using the visited network. Typically, once the device selects the system in which to establish a wireless communication, the mobile device must register itself with the system in order to avail itself to the wireless services provided by the selected system. The registration process requires a mobile subscriber identity.
More recently, in addition to selecting a preferred network, the wireless network operators may have begun to provide subscriber devices with multiple identities for various reasons. With subscriber devices having multiple identities, the selection of a single identity at a time is required to register the subscriber device with a given network at a given time. Therefore, an attendant need has arisen for such a device to select from among its assigned identities as it roams and registers with various networks. In one example, each identity may be tied to a different home network. The home networks may in some cases belong to business partners, or in other cases belong to different subsidiaries of a parent organization. In addition, each home network may have different roaming agreements with different network operators in various areas or countries. In order for a subscriber to take advantage of the best roaming agreement, e.g., in financial terms, a particular mobile subscriber identity would be preferable to another when registering for service on a visited network.
In another example of a subscriber having multiple identities, an enterprise customer may be provided with different identities that have service agreements based on time-of-day use. In the same area, a visited network may offer better roaming rates than another based on the time of day or the day of the week that service is requested. Therefore, in order for a subscriber to take advantage of the best roaming agreement, e.g., the least expensive roaming rates, a particular mobile subscriber identity would be preferable to another when registering for service on the visited network.
As noted, once the device selects the system or network in which to establish a wireless communication, the mobile device must register itself with the system in order to avail itself of the wireless services provided by the selected system; and that registration process requires a mobile subscriber identity. In the case of 3GPP technologies, the mobile subscriber identity is represented by an IMSI. In the case of 3GPP2 technologies, the mobile subscriber identity is represented by an MDN/MIN pair, or an MDN/MSISDN/MIN pair. In the case of WLAN or WiMAX, the mobile subscriber identity can be extended to and represented by an APN, NAI, etc.
One solution for registering a subscriber device having multiple identities would be to select the last used identity of the subscriber device and attempt to register that identity for wireless communications service on the selected network. The selected network would determine whether the identity is desired, and reject the identity if not desired. If rejected, another identity would be selected, and the subscriber device would make another attempt to register the identity with the selected network. This process would continue until the registration succeeded or failed after a predetermined number of attempts. At that point, the device may attempt to select another network, e.g. the next most preferred network if one is available, and repeat the processing of trying one or more of its identities until the device successfully registers. The nature of this solution, i.e., request-reject-retry, creates delays in registration by requiring repeated attempts even with the first selected network, and may require additional time to scan for alternative networks, read broadcast messages, select the system, and perform registration with the network selected for that registration attempt.
Hence, there is a need for improvement in the technique to select an identity of a subscriber device having multiple identities and register the selected identity with a network for wireless communications, in a way that takes advantage of the most favorable roaming agreements between operators, e.g. for domestic and international roaming.